[PATCH 5/6] transport-pci: Add missing driver requirement for admin queue fields

[Parav Pandit <parav@nvidia.com>]

The description of admin_queue_index and admin_queue_num in the common
configuration structure already states that these fields are valid
only if VIRTIO_F_ADMIN_VQ has been negotiated. However, the
corresponding driver requirement was missing from the normative
statements.

Add this missing requirement: the driver must not access
admin_queue_index and admin_queue_num unless VIRTIO_F_ADMIN_VQ has
been negotiated. This does not change the existing behaviour; it only
captures what was already part of the specification as a normative
statement, and aligns the PCI transport with the equivalent MMIO
transport requirement for AdminQueueIndex and AdminQueueNum.

Fixes: 677aeaebf6a7 ("pci: add admin vq registers to virtio over pci")
Signed-off-by: Parav Pandit <parav@nvidia.com>
---
 transport-pci.tex | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/transport-pci.tex b/transport-pci.tex
index 95b08b8..0cd9eab 100644
--- a/transport-pci.tex
+++ b/transport-pci.tex
@@ -523,6 +523,9 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
 were used before the queue reset.
 (see \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset}).
 
+The driver MUST NOT access \field{admin_queue_index} and
+\field{admin_queue_num} unless VIRTIO_F_ADMIN_VQ has been negotiated.
+
 If VIRTIO_F_ADMIN_VQ has been negotiated, and if the driver
 configures any administration virtqueues, the driver MUST
 configure the administration virtqueues using the index
-- 
2.43.0